(i) Field of the Invention
This invention relates to a method and apparatus for mounting davit assemblies on rooftops. More particularly, the invention relates to an improved davit system that is portable and can be installed flush to or projecting upwardly from the rooftop.
(ii) Description of the Related Art
Roof top davit systems have long been used by workmen for window washing, painting, maintenance, and the like. It is common practice to provide pairs of davits from which scaffolding can be lowered and raised on the outside of buildings using suspension lines.
U.S. Pat. No. 4,545,558 was granted Oct. 8, 1985 to Richard E. Crudele for a platform suspending davit mounting apparatus and method. The invention includes a mounting socket assembly with wheels and a handle for movement, and a locking clamp to engage a mounting pedestal platform. The socket is adapted to receive a davit.
U.S. Pat. No. 5,782,446 granted to Ali Ghahremani Jul. 21, 1998 describes a davit mounting assembly mounted on a generally circular mounting plate for positioning of the davit mounting assembly at any rotational angle.
The present invention provides an improved portable davit mounting assembly and method for removable attachment to a rooftop pedestal and mounting plate. The davit mounting assembly has a simple design with few parts. The rooftop pedestal and mounting plate can be installed flush to the rooftop when aesthetics or pedestrian traffic are of concern. The portable davit base adaptor is lightweight and comes with handgrips, so that one person can carry it.
In its broad aspect, the davit mounting assembly of the assembly includes a mounting plate for attachment to a davit pedestal, and a portable davit base adaptor assembly having a pair of spaced-apart opposed side plates joined together by a pair of transverse support members fixedly attached to said side plates. The mounting plate includes two pairs of spaced-apart foot apertures and a mounting plate securing pin aperture located between each pair of spaced-apart foot apertures. The opposed side plates each have front and back davit pin apertures formed in axial alignment with corresponding apertures of the opposed side plate such as to form two pairs of base adaptor pivot pin apertures, each pair able to receive a davit pivot pin, and each pair of base adaptor pivot pin apertures being in further alignment with the corresponding transverse support member. Each side plate has downwardly extending legs, front and back, with feet adapted to be received by and interlocked with the mounting plate foot apertures. Each said transverse support member has a vertical aperture for receiving a securing pin for vertical alignment and securement with a mounting plate securing pin aperture when both pairs of feet are interlocked with pairs of mating mounting plate foot apertures, such that insertion of a davit pivot pin in a pair of aligned side plate base adaptor pivot pin apertures blocks removal of the securing pin whereby the pairs of feet interlocked with mating apertures are prevented from removal.
More specifically, the davit mounting assembly is assembled by inserting the legs and interlocking feet of the portable davit base adaptor assembly into the foot apertures of the mounting plate of the fixed davit pedestal and moving the portable davit base adaptor laterally to engage the fitted legs and feet with the mounting plate. Securing pins are then inserted through the transverse member securing pin holes and into the mounting plate securing pin apertures, thusly attaching the portable davit base adaptor to the mounting plate.
Each side plate leg has an enlarged distal foot and each aperture is a key hole comprising an enlarged slot adapted to receive an enlarged distal foot therethrough and a narrow slot adjacent the enlarged slot for lateral reception of a leg therein, whereby the enlarged distal feet can engage and become hooked to the mounting plate.
A transverse member securing pin hole and mounting plate securing aperture, with the securing pin inserted, are equidistant between one pair of the concentric base adaptor pivot pin apertures, such that the centre axis line of the inserted securing pin will extendedly intersect with the axis of the concentric base adaptor pivot pin apertures, thusly, when a linear davit pivot pin is inserted in the base adaptor pivot pin apertures it will be directly above the installed securing pin, locking the securing pin in place. This also ensures that the looking pin is in place and engages the base mounting plate before the davit pins can be inserted.
A davit mast, which has at its base pivot pin apertures designed to fit inside of the base adaptor pivot pin apertures, can be installed using davit pivot pins.